Elevation from Grade and Distance

E2=E1+G L100E_2 = E_1 + \frac{G\,L}{100}

Worked example: 250.0 m to 256.5 m over 130 m → 5 % grade — press Try an example to run it live, then adjust anything.

Enter your known values, leave one input blank, and solves for the missing one. Tap a variable’s symbol to see what it means, with a typical value. Try different units for next level excitement!

Here the solver did the work — could you?

Elevation on the grade →

UniversityApplied Field Engineering

Test your skills in the Exam Room: new numbers every attempt — free lessons for students, no sign-up, just pure learning. Find 2 more lessons on this formula.

See your Report Card
Compete with your friends
share your results
Learning zone

Elevation from Grade and Distance explained

GLE1E2

This is the single most-used line of arithmetic on a construction site: take a known elevation, walk a measured horizontal distance, and add the grade times that distance. Sign discipline is everything — enter a fall as a negative grade and the formula keeps track for you. It is the same relation that sets pipe inverts: an 8 in sanitary lateral run at −2.0 % from an invert of 253.40 m over 42 m arrives at 253.40 − 0.84 = 252.56 m, and if the downstream structure was built at 252.70 the pipe will not drain and someone is coming back with a saw.

Solved for G it becomes the as-built check — measure both ends, divide the difference by the run — and solved for L it answers the layout question, "how far out do I stake the daylight point?" A worked example: a 1.5 % crowned road starting at 431.20 ft crown elevation reaches 431.20 + 1.5 × 260/100 = 435.10 ft at station 2+60. The trap is using the taped slope distance for L instead of the horizontal projection; on flat grades the error hides, on steep ones it does not.

Elevation from Grade and Distance formula

E2=E1+G L100E_2 = E_1 + \frac{G\,L}{100}
Where
  • E2E_2= Elevation at the far point (m)
  • E1E_1= Known starting elevation (m)
  • GG= Grade (%)
  • LL= Horizontal distance (m)

Missing one of these? Work it out first, then come back